A process according to the preamble of claim 1 is known from DE 10 2009 055 942 B4 is a regenerative thermal combustion system, the carbon compounds are oxidised in the multi-stage combustion chamber at a temperature of more than 800° C. and the nitrogen oxides are thermally reduced by adding a nitrogen-hydrogen compound.
In the production of cement, but also in other industrial processes where fuels are combusted to generate high temperatures, environmental protection aspects as well as raw material and fuel costs are playing an increasingly important role. In particular, emissions of nitrogen oxides (NOx), ammonia (NH3) and carbon monoxide (CO) are to be reduced, while fuel and raw material costs are to be reduced by a reduction in the quantity of fuel as well as low-cost fuels and raw materials, so-called secondary fuels or secondary raw materials. In addition to organic carbon compounds, such gases also contain carbon monoxide and ammonia. When the ammonia (NH3) or urea used as a reducing agent is dosed into the combustion chamber, there is a risk that an ammonia slip will occur as a by-product and therefore harmful ammonia will escape into the atmosphere.
The object of the invention is to provide waste gas purification, in particular for the cement industry, which reduces emissions of organic pollutants as well as carbon monoxide, nitrogen oxides and ammonia by reducing fuel/raw material costs.